Trough-shaped luminaire with housing



June 27, 1967 A. B. GOUGH TROUGH-SHAPED LUMINAIRE WITH HOUSING 6Sheets-Sheet 1 Filed June 4, 1965 June 27, 1967 A B, GOUGH 3,328,578

THOUGH-SHAPED LUMINAIRE WITH HOUSING Filed June 4, 1965 6 SheetsShee 2June 27, 1967 A. B. GOUG'H TROUGH-SHAPED LUMINAIRE WITH HOUSING 6Sheets-Sheet 5 Filed June June 27, 1967 GOUGH 3,328,578

THOUGH-SHAPED LUMINAIRE WITH HOUSING Filed June 1965 6 Sheets-Sheet 4June 27, 1967 GOUGH 3,328,578

TROUGH-SHAPED LUMINAIRE WITH HOUSING Filed June 4, 1965 6 Sheets-Sheet 5June 27, 1967 B GQUGH THOUGH-SHAPED LUMINAIRE WITH HOUSING 6Sheets-Sheet 6 Filed June 4, 1965 United States Patent 3,328,578TROUGH-SHAPED LUMINAIRE WITH HOUSING Alfred B. Gough, Flat Rock, N.C.,assignor to General Electric Company, a corporation of New York FiledJune 4, 1965, Ser. No. 461,340 Claims. (Cl. 24093) ABSTRACT OF THEDISCLOSURE Tunnel luminaire comprises upper trough-shaped housing closedby a transparent refractor with longitudinal prisms and separablysecured along opposite sides to the housing by a plurality of combinedlatch and hinge means, the joints between the parts being in fluid-tightengagement.

The present invention relates to luminaires, and more particularly toelongated luminaires adapted for lighting tunnels and underpasses.

It is an object of the invention to provide a luminaire of the abovetype having improved means for latching the refractor to the housing toenable ready access to the interior of the housing for relamping,cleaning and other maintenance operations.

It is another object of the invention to provide a luminaire of theabove type having an improved optical system including reflector andrefractor structures for effective control of light distribution.

A further object of the invention is to provide improved fluid-tightsealing means at the joints of the luminaire housing and refractorassemblies.

Other objects and advantages will become apparent from the followingdescription and the appended claims.

With the above objects in view, the present invention in one of itsaspects relates to a luminaire comprising, in combination, an upperinverted trough-shaped housing having a top and opposite side portions,a lower troughshaped refractor forming a closure for said housing, thehousing having first support means projecting inwardly from its oppositeside portions, a reflector having opposite sides engaging the firstsupport means and dividing the interior of the enclosedhousing-refractor unit into upper and lower compartments, the housinghaving second support means projecting downwardly from its top,electrical operating components in the upper compartment supported bythe second support means, lampholder means for mounting lamp means inthe lower compartment, and combined latch and hinge means holdingopposite sides of the refractor inv closed, fluid-tight engagement withthe housing.

As more fully described below, the refractor is formed with longitudinalprisms on its outer surface to provide uniform dispersion of light fromthte luminaire, the refractor being provided with molding strips alongits upper edges which securely engage the refractor and provideeffective sealing means with the housing.

The invention will be better understood from the following description,taken in conjunction with the accompanying drawings, in which:

FIGURE 1 is a perspective view of an embodiment of a tunnel luminaireconstructed in accordance with the invention;

FIGURE 2 is an enlarged perspective view in section of a portion of theFIGURE 1 luminaire as viewed along the line 2-2 of FIGURE 1;

FIGURE 3 is a side elevational view, partly broken away, of the FIGURElluminaire;

FIGURE 4 is a fragmentary end elevational view of the luminaire takenalong the line 44 of FIGURE 3;

3,328,578 Patented June 27, 1967 FIGURE 5 is a fragmentarycross-sectional view of the luminaire taken along the line 55 of FIGURE3;

FIGURE 6 is a fragmentary cross-sectional view of the luminaire takenalong the line 6-6 of FIGURE 3;

FIGURE 7 is an enlarged detailed view, partly in section, of thelatching and adjacent parts of the luminaire;

FIGURE 7a is a detail view in cross-section of the end wall gasket shownin FIGURE 7;

FIGURE 8 is a fragmentary perspective View partly in section of meanssupporting a terminal board in the luminaire;

FIGURE 9 is a fragmentary side view of the optical system of theluminaire, including a ray diagram; and

FIGURE 10 is a fragmentary cross-sectional view of the luminaire opticalcomponents, including a ray diagram.

Referring now to the drawings, and particularly to FIGURE 1, there isshown a luminaire of a type adapted to be used for lighting tunnels orunderpasses and comprising an elongated housing 1 of a metal such asaluminum having an upper hood portion 1a and end walls 112,

1c, and a transparent cover or refractor 2 enclosing the bottom ofhousing 1 and releasably attached to both sides of the latter bycombination hinge-latches 3 spaced along the opposite longitudinal edgesof hood 1a. Brackets 4 and 4 secured at opposite ends of housing I serveto mount the luminaire on a suitable support, such as on the wall orroof of the tunnel or underpass, with the longitudinal axis of theluminaire parallel to the roadway.

In the embodiment shown (see FIGURE 4), each mounting bracket 4, 4 hasan aperture at its lower end fitting loosely over an annular ridge 1which surrounds a corresponding aperture in the end wall, and an annularclamping plate 5 releasably clamps brackets 4, 4' to the respective endwalls in the desired angular position by means of screws 6. Theluminaire may thereby be rotatably adjusted about its longitudinal axisto aim it toward the roadway in the optimum angular position. The innersurface defining the apertures in end walls 1!), 1c and in the annularridges projecting therefrom is formed with screw threads for threadablyengaging a tubular conduit 7 for carrying electrical conductors.Alternatively the end wall may be formed with a clearance hole forreceiving a threaded conduit tube, and suitable lock nuts and gaskets(not shown) are employed to secure the conduit tube in place with afluid tight fitting. I

As best seen in the cutaway view of FIGURE 2, an elongated reflector 10,such as a sheet of aluminum, is mounted with its longitudinal edges 10a,10b engaged in opposite C-shaped channels 11a, 11b formed on the innersurface of housing 1. These longitudinal reflector edges are providedalong limited regions thereof with flared-out portions, as indicated byportion 10d in FIGURE 7, so that when the reflector is snapped intoplace in opposite channels 11a, 11b, the flared portions 10d maintainpressure to keep the reflector from vibrating or falling out. Typically,such flared-out portions 10d are provided two to a side and opposite oneanother, and the removal of the reflector from the housing is readilyeffected by grasping the sides of the reflector adjacent these portionsand compressing the reflector to move its longitudinal edges out of theretaining channels 11a, 11b. Replacement of the reflector in the housingis achieved in similar fashion.

Reflector 10 is further preferably formed with a bend portion extendingcentrally along its length, thereby providing two concave reflectorportions facing the lamps in the lower compartment for properlydistributing the reflected light throughout the transparent refractor 2.Bend 100 also provides for the desire-d degree of resiliency in thealuminum reflector sheet for yieldably retaining its edges in engagementwith housing channels 11a, 1112, while still permitting ready removaltherefrom by compressing the sides, as described.

Reflector divides the interior of housing 1 into a lower compartmentoccupied by elongated fluorescent lamps 12 and an upper compartment inwhich are located electrical components such as ballasts, conductors,terminal boards and associated parts. At each end of the lowercompartment (see FIG. 6) a lamp holder plate 15 is secured, e.g., byscrews 16, to supporting bosses (not shown) projecting inwardly fromhousing end walls 1b, 1c. Each lamp holder plate 15 is provided withsockets 17 for receiving and holding the contact ends of lamps 12..

Each end wall 1b, 10 comprises a plate member, e.g., of aluminum,secured by screws or the like to hood 1a and having an inwardlyprojecting continuous ridge (see FIGURE 6) which follows a tortuous pathgenerally along the upper edge portion of the end wall and which has agenerally U-shaped form along the lower edge portion to which aresilient gasket 21 is secured on the outward side thereof. The innersurface of hood 1a is formed with ribs 22 and 22a which are generallycomplementary to the indentations formed in upper ridge 20 and which inthe assembly of the end walls on hood 1a interfit with thoseindentations. However, sufficient space is left therebetween in which anon-hardening, elastomeric sealing material 23, such as silicone rubbercompound, which is capable of withstanding weathering and vibration overa wide temperature range, is introduced to ensure a fluid-tight seal atthis joint. As seen in FIGURE 2, longitudinal part-circular channels 18,19 and 18', 19' are formed in the inner surface of hood 1a extendingalong the length theerof. Thread-forming screws 18a, 19a (see FIGURE 4and FIGURE 6) serve to hold the end walls on hood 1a by being screwedinto the respective channels 18 and 19.

As shown in the detail view of FIGURE 7a, gasket 21, which is secured tothe lower U-shapedportion of ridge 20 is preferably hollow with spacedexternal ribs and made of a resilient material, such as extrudedneoprene rubber or silicone elastomer which is resistant to compressionset, so that when refractor 2 is in closed position on housing 1, itbears at its opposite ends on gasket 21 and compresses it to provide afluid-tight seal at this joint.

As seen in FIGURES 2 and 5, there are located in the upper housingcompartment a plurality of cable retainers 25 in the form of strips eachhaving a looped lower end portion 25a and a bent upper end portion 25b,and having an intermediate bend portion which serves to resiliently urgethe end portions into engagement with longitudinal channels 18 and 19formed in the sides and top of hood 1a. Looped portion 25a issufficiently large in diameter to be held captive in channel 18 (seeFIGURE 7), whereas bent end portion 25b may be removed from channel 19(see FIGURE 5) simply by compression of strip member 25. Strip members25 are arranged in spaced positions along the length of hood In on oneor both sides thereof, and in this assembly they serve to retain inplace the main power supply cables C (see FIGURE 2) strung along theupper corners of the housing when the luminaire is installed.

The roof of hood 1a is formed with dependent L- shaped projections 26,27 facing each other and running along the length of the hood, theseprojections serving as support rails for retaining in positionelectrical components of the luminaire located in the upper compartment.Cross bars 29 arranged at opposite ends of ballast unit 28 (see FIGURES3 and 5) rest at their opposite ends on projections 26 and 27 and areprovided with screws 30 threaded therein which bear against end flangeson ballast unit 28, clamping the latter against ribs 22, 22a on the roofof hood 1a and serving to retain it in fixed position. Ribs 22, 22a thusalso serve as heat transfer means for maintaining ballast 28 at theproper operating temperature.

As shown in FIGURE 8, a pair of superposed flat cross members 31, 32secure terminal board 33 in position by clamping rails 26 and 27 betweenthem at opposite ends by means of screws 34 which pass through a flangeon terminal board 33 and are threaded through clamping cross members 31,32. Another pair of cross members is similarly arranged at the oppositeend of terminal board 33 for securing that end.

In luminaires of relatively short lengths, say 4 ft. or less, reflector10 extends along the luminaire in one piece. In longer luminaires, suchas those made in multiples of 4 ft. lengths, the reflector is made intwo or more separate sections. In such cases, it is desirable to providea tie bar 50 (see FIGURES 5 and 7) extending laterally across housing 1and arranged between adjacent sections of reflector 10. Tie bar 50 inthe embodiment shown comprises main member 50a of U-shaped cross-section(see FIGURE 3) formed with grooves 50b spaced inwardly from oppositeends, and clamp members 51 each having depending inner and outer flangesand separably secured to main member 50a by a screw 52. Each clampmember 51 is arranged with its inner flange fitting into groove 5% andits outer flange in the recess formed behind channel 11a. Main member 50is notched at its ends to receive the upper portion of channel 11a, sothat when tie bar 50 is assembled with clamp 51 and the notched end ofmember 50a engaging opposite surfaces of the upper portion of chan: nel11a, screw 52 is tightened, and the other end of, tie bar 50 issimilarly secured to channel 11b. In this way, tie bar 50 serves toretain housing 1 in the proper lateral dimensions and stabilize itsform, especially in relatively long luminaires.

Refractor 2 of the luminaire is generally trough-shaped and is made of atransparent material, such as a synthetic plastic, e.g.,methylmethacrylate, and is formed around its exterior surface with aplurality of prisms extending along its length, as shown in FIGURE 2. Oneach upper edge of refractor 2 is clamped a metal molding strip 40, suchas of aluminum, which, as shown best in the enlarged view of FIGURE 7,has a fiat inner portion 40a, a doubleflanged outer rail portion 40b,and an inwardly facing gripping portion 400 having upper and lowerbearing sur faces at an angle to one another and formed to tightly gripthe angled faces of the uppermost .prism on refractor 2 when metalmolding 40 is clamped alongthe upper edge of the refractor. Moldingportion 400 is formed to provide an opening between the molding and theengaged refractor portion in which a sealing material 41, such as asilicone rubber or other oil-soluble elastomer that can withstand saltspray, weathering, vibration and other environmental extremes oftemperature, is introduced to provide a fluid-tight seal at this jointwhen the molding 40 is clamped in place over the edge of refractor 2.The.

remaining opening 42 between molding 40c and the upper edge of refractor2 is filled at the opposite ends of the refractor with similar sealingmaterial.

Sealing gasket 43, made of sponge rubber or the like, is secured alongthe underside of rim 1d of the housing which is formed with an outer lip1e overhanging the gasket seal surface, and forming therewith aprotected recess in which gasket 43 is located. When refractor 2 is inassembled position closing the interior of housing 1, the uppermost edgeof molding 40 engages and compresses gasket 43 and outer bearing surface40d of molding 40 comes into mating engagement with the bottom edge oflip 1e of the housing, as seen in FIGURE 2. There are thus provided anouter bearing surface and an inner seal surface bywhich the housing 1mates with molding 40 on refractor 2, and in the closed position ofrefractor 2 there is thus afforded on opposite sides of the assemblyeffective fluid-tight seals between the exte-,

rior and the interior of the housing at these joints.

Refractor 2 is held in tightly closed position by means of hinge-latches3 which are pivotally attached to housing 1 and which engage hookmembers 45 secured to refractor molding 40, as seen in FIGURE 7. Eachlatch assembly 3 comprises a mounting portion 3a fixedly secured to hoodla and having spaced outwardly extending flanges, a lever portion 3bsecured by pivot pin 30 to the flanges of lever portion 3b for pivotingabout an axis parallel to the longitudinal axis of housing 1 and a wireloop member 3d swingably attached to lever portion 31) at alignedapertures therein spaced above and somewhat inwardly of the axis ofpivot pin 30, as seen in the locked position of the latch in FIGURE 7.In the fully closed position of refractor 2 as shown in FIGURES 2 and 7,the flanges of fixed mounting portion 3a straddle hook 45, 100p member3a engages hook 45 and seats in recesses provided at the bottom of theflanges of mounting portion 3a, and lever portion 312 is in the lockedupper position after being pressed toward hood 1a until the plane ofwire loop member 3d is positioned inwardly of the axis of pivot pin 3c.Such locking is effected by the inherent resiliency of wire loop member3d, which permits it to be snapped over center, i.e., beyond the axis ofpivot 30, while in engagement with latch book 45, and while loop member3a. resiliently urges the mating parts of refractor 2 and hood 1adescribed above into fluid-tight sealing engagement with one another.

As seen in FIGURE 7, hood 1a is formed along its length with a channel1g in which mounting portion 3a 18 slidably received during assembly sothat the latter member may be positioned anywhere along the hood andthen fixed in the desired position simply by peening or otherwiseindenting the web of mounting portion 3a to fixedly secure it in channel1g and prevent it from sliding therealong. Portion 3:; may alternativelybe welded, riveted or otherwise fixed in the desired position in channel13.

Similarly, hook member 45 slidably engages rail flanges 40b by meansshOWn in FIGURE 7 and may be fixed in desired position thereon in themanner described in connection with latch member 3a.

To open latch 3, lever portion 3b is pulled outwardly and downwardlyabout its pivot axis so that loop member 3:! drops out of engagementwith latch hook 45 and the recesses at the bottom of the flanges ofmounting portion 3a. When all the latches 3 along one side of theluminaire are so disengaged, refractor 2 is still swingably attached tohousing 1 by loop members 3d of the latches along the opposite side ofthe housing, that is, hook 45 swings about loop member 3d as a hinge,and thus refractor 2 may be swung away from the housing along one sideto provide ready access thereto for necessary maintenance and repair.

As seen best in FIGURE 10, the longitudinal external prisms 2a formed onthe outside surface of refractor 2 are arranged side by side throughoutthe entire extent of refractor 2. The inner surface of refractor 2 isformed with a series of convex portions 211 arranged opposite theexternal prisms and extending along the length thereof. These convexrefractor portions serve in combination with external prisms 2a toproduce a uniform, glare-free dispersion of light emanating from theluminaire. As seen from the ray diagrams in the cross sectional view ofFIGURE 10, the light rays from the adjacent lamp (as well as lightreflected by reflector 10) are collected by the internal convex portions221 and refracted thereby toward the external prisms which distributethe light rays externally. Internal reflection by the inner surface ofrefractor 2 is thereby substantially reduced. However, as will be seenfrom the ray diagrams in the fragmentary elevational view of FIGURE 9,those light rays which strike the refractor at relatively great anglesin the planes parallel to the length of the luminaire are for the mostpart either reflected internally or refracted by the external prisms toemanate at angles which do not cause glare to oncoming motorists.

There is thus provided in accordance with. the invention, a luminairestructure which is readily mounted and adjusted for use in illuminatingtunnels and underpasses,v

which is weatherproof and rugged in construction, which is readilyopened for access to the interior for maintenance and repair, and whichprovides uniform illumination of the tunnel areas while avoiding glarefor oncoming motorists, as well as other advantages.

While the present invention has been described with reference toparticular embodiments thereof, it will be understood that numerousmodifications may be made by those skilled in the art without actuallydeparting from the scope of the invention. Therefore, the appendedclaims are intended to cover all such equivalent variations as comewithin the true spirit and scope of the invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. In a luminaire, an elongated inverted trough-shaped housing havingopposite end walls closing the opposite ends thereof, each end wallbeing formed along its inner surface adjacent the upper edge thereofwith a continuous ridge extending transversely of said housing in atortuous path, the underside of said housing having downwardlyprojecting ribs formed therein, the end portions of which are receivedin recesses formed in said ridge, and yieldable sealing means occupyingthe remainder of said recesses for fluid-tightly sealing the jointsbetween said housing and said end walls thereof.

2. In a luminaire, an elongated inverted trough-shaped housing havingopposite end walls closingthe opposite ends thereof, each end wall beingformed along its inner surface adjacent the upper edge thereof with acontinuous ridge extending in a tortuous path, said housing havingprojecting ribs formed therein, the end portions of which are receivedin recesses formed in said ridge, yieldable sealing means occupying theremainder of said recesses for fluid-tightly sealing the joints betweensaid housing and said end walls thereof, each said end wall having aprojecting lip forming a U-shaped continuation of said ridge andextending along and spaced inwardly from the lower edge of said endwall, resilient gasket means secured to said projecting li atrough-shaped refractor forming a closure for said housing and engagingsaid gasket means at opposite ends in sealing relation therewith, andlatch means holding said refractor in closed, fluid-tight sealingrelation with said housing.

3. A lighting fixture comprising, in combination, an upper invertedtrough-shaped housing having a top and opposite side portions, 3. lowertrough-shaped refractor forming a closure for said housing, said housinghaving first support means projecting inwardly from its opposite sideportions, a reflector having opposite sides engaging said first supportmeans and dividing the interior of the enclosed housing-refractor unitinto upper and lower compartrnents, said housing having second supportmeans comprrsmg spaced elongated ribs of L-shaped cross section facingeach other and depending from said top of said housing, a plurality ofcross members extendingbetween and supported at their ends by saidspaced depending ribs, electrical operating components in said uppercompartment secured to and supported by said cross members, lamp holdermeans for holding lamp means in said lower compartment, and combinedlatch and hinge means holdrng said refractor in closed, fluid-tightengagement with said housing.

4. A lighting fixture comprising, in combination, an upper invertedtrough-shaped housing having a top and opposite side portions, a lowertrough-shaped refractor forming a closure for said housing, said housinghaving first support means projecting inwardly from its opposite sideportions, a reflector having opposite sides engaging said first supportmeans and dividing the interior of the enclosed housing-refractor unitinto upper and lower compartments, said housing having second supportmeans projecting downwardly from its top, electrical operatingcomponents in said upper compartment supported by said second supportmeans, lamp holder means for holding lamp means in said lowercompartment, combined latch and hinge means holding said refractor inclosed, fluid-tight engagement with said housing, and a plurality ofspaced elongated resilient members extending between and engaged attheir ends respectively at said first and second support means forretaining electrical conductors in said upper compartment.

5. In a luminaire, an upper inverted trough-shaped housing, a lowertrough-shaped refractor forming a closure for said housing, moldingstrip means embracing and extending along the. opposite upper edges ofsaid refractor, said molding strip means and said housing each havingouter bearing surfaces and inner sealing surfaces mating with each otherin closed assembly, gasket means between said mating inner sealingsurfaces, and combined latch and hinge means holding said refractor inclosed, fluid-tight engagement with said housing, and comprising a basemember secured to said housing adjacent the bearing surfaces thereof andhaving spaced outwardly projecting flange portions, a lever memberpivoted at one end to said flange portions, a wire loop member swingablysecured to said lever member, and a hook member fixed to said moldingstrip means of said refractor, said wire loop being engageable with saidhook member, and said lever member being movable about its pivot axistoward said housing for retaining said wire loop member in said hookmember, said refractor being swingable about said wire loop member whilethus retained in said hook member.

6. In a luminaire, an upper inverted trough-shaped elongated housing, alower trough-shaped elongated refractor forming a closure for saidhousing, molding strip means embracing and extending along the oppositeupper edges of said refractor, said molding strip means and said housingeach having outer bearing surfaces and inner sealing surfaces matingwith each other in closed assembly, gasket means between said matinginner sealing surfaces, a plurality of combined latch and hinge meansspaced from each other on each side of said assembled housing andrefractor, each combined latch and hinge means holding said refractor inclosed, fluid-tight engagement with said housing, and comprising a basemember secured to said housing adjacent the bearing surfaces thereof andhaving spaced outwardly projecting flange portions, a lever memberpivoted at one end to said flange portions, a wire loop member swingablysecured to said lever member, and a hook member fixed to said moldingstrip means of said refractor, said wire loop being engageable with saidhook member, and said lever member being movable about its pivot axistoward said housing for re taining said wire loop member in said hookmember, said refractor being swingable about said wire loop member whilethus retained in said hook member and when the combined latch and hingemeans on the opposite side are disengaged.

7. In a luminaire, an elongated housing, an elongated refractor forminga closure for said housing, molding strip means secured to the edge ofsaid refractor adjacent said housing, said housing and said moldingstrip means each being formed with supporting rail means extending alongtheir length, and combined latch and hinge means mounted on said railmeans of said housing and said molding strip means for holding saidhousing and said refractor in closed assembly said combined latch andhinge factor in closed assembly, said combined latch and hinge meanswhen initially assembled on said housing and said molding strip meansbeing slidable along said respective supporting rail means topredetermined position thereon.

8. A luminaire, comprising, in combination, an elongated invertedtrough-shaped housing, an elongated trough-shaped refractor forming anenclosure for said housing and having upper longitudinal edges adjacentsaid housing in its closed position, molding strip means embracing andextending along said opposite upper longitudinal edges of saidrefractor, fixed latch means on one.

by side along the length thereof, each of said prisms on.

said refractor having prism faces at an angle to one another, saidmolding strip means being formed with angularly arranged bearingsurfaces complementary to said angularly arranged prism faces andgripping thereby the prism faces of the uppermost prisms of saidrefractor.

9. A luminaire as defined in claim 8, wherein said molding strip meansis formed with a recess at the junction of said angularly arrangedbearing surfaces, said recess being filled with resilient sealing meansfor sealing the joint between said molding strip means and saidrefractor.

10. A luminaire comprising, in combination, an elongated invertedtrough-shaped housing, and elongated trough-shaped refractor forming anenclosure for said housing and having upper longitudinal edges adjacentsaid housing in its closed position, molding strip means embracing andextending along said opposite upper longitudinal edges of saidrefractor, hook means secured to said refractor molding strip means,latch means pivotally secured to said housing and having a wire loopmember swingably secured thereto, said wire loop member being engageablewith said hook member, and said latch member being movable about itspivot axis toward said housing for retaining said wire loop member insaid hook member, said refractor being swingable about said wire loopmember while thus retained in said hook member.

References Cited UNITED STATES PATENTS 2,474,341 6/1949 Wince 240-932,731,288 1/1956 Langford 292258 2,775,001 12/1956 Baker 292-2582,926,238 2/1960 Anderson et al 240-51.11 3,233,094 2/ 1966 Foulds 24025FOREIGN PATENTS 80,146 2/1951 Czechoslovakia.

NORTON ANSI-1BR, Primary Examiner.

WYNDHAM M. FRYE, Assistant Examiner,

1. IN A LUMINAIRE, AN ELONGATED INVERTED TROUGH-SHAPED HOUSING HAVINGOPPOSITE END WALLS CLOSING THE OPPOSITE ENDS THEREOF, EACH END WALLBEING FORMED ALONG ITS INNER SURFACE ADJACENT THE UPPER EDGE THEREOFWITH A CONTINUOUS RIDGE EXTENDING TRANSVERSELY OF SAID HOUSING IN ATORTUOUS PATH, THE UNDERSIDE OF SAID HOUSING HAVING DOWNWARDLYPROJECTING RIBS FORMED THEREIN, THE END PORTIONS OF WHICH ARE RECEIVEDIN RECESSES FORMED IN SAID RIDGE, AND